Normally, door locks of this type have a lock cylinder disposed in the door and braced against the outer side of the door, while on the inner side of the door, a mounting plate is provided and secured to the cylinder, so that both the plate and the cylinder mutually support one another.
The plate is provided with a plurality of holes in registration with respective holes in the bolt casing, and which are traversed by casing screws which also traverse the plate holes and serve to mount the casing directly to the door.
In a forced entry situation, the casing screws securing the bolt casing to the door are torn out of the screw holes in the door and in the process, these screw holes are destroyed and cannot be used again for holding a screw, so that the entire lock assembly must be relocated to another part of the door, and the destroyed portion of the door must be repaired, as well as the bore in which the cylinder was disposed.